This invention pertains generally to arrows used for hunting, target practice, archery competitions and the like, and more particularly to processes and devices for attaching an arrowhead to an arrow shaft.
More than a dozen different diameter arrow shafts are currently available to archers. Customarily, various different styles of arrowheads have been made for use with each of a variety of different diameter arrow shafts. As a result, an arrowhead manufacturer that wishes to supply two different styles of arrowheads, (e.g., one broad head and one field tip) for 10 different arrow shaft diameters would need to manufacture 20 different arrowheads. Thus, arrowhead manufacturers typically invest in tooling and equipment for making dozens of different types of arrowheads. Therefore, manufacturers would find it desirable to provide a full range of different types of arrowheads for every available shaft diameter while reducing manufacturing expenses by reducing the amount of tooling and equipment needed to provide a full range of products. In addition, retailers and consumers would benefit if a full range of products could be achieved with fewer components. Accordingly, it would be desirable to provide a means by which an arrowhead can be easily attached to any of a variety of different diameter arrow shafts.
Conventional arrows typically comprise a coupling or insert received in a forward end of an arrow shaft and an arrowhead that is attached to the coupling or insert by way of a threaded connector, whereby the arrowhead is screwed onto the coupling or insert. A disadvantage with this type of arrangement is that unless a level of care beyond that typically exercised in the manufacture of such parts is maintained, slight misalignment of the parts during machining of the threads will result in misalignment of the arrowhead with the arrow shaft. The resulting lack of symmetry, parallelism and concentricity with respect to the longitudinal axis of the arrow will adversely affect the flight of the arrow and reduce accuracy. In addition assembly is difficult and cumbersome due to the threaded connections. Also, care must be taken during assembly to avoid misalignment of the threads and cross threading which would further acerbate problems associated with a lack of symmetry of the arrowhead with respect to the longitudinal axis of the arrow. Accordingly, it would be desirable to provide a means of attaching an arrowhead to an arrow shaft which is easier and ensures excellent symmetry of the arrowhead with respect to the longitudinal axis of the arrow.
A fundamental requirement for optimum arrow performance is that the arrow be properly balanced to attain good arrow flight. An arrow with too little weight at its front will tend to tumble. Arrows must typically have extra weight at the front end to provide guidance for the remainder of the shaft in flight. Various devices and mechanical arrangements have been devised to add and adjust the total weight of an arrow point within a desired overall total weight range. A preferred known means for adjusting the weight and balance of an arrow is a grain rod attachable to the arrow tip. A preferred grain rod is one having a plurality of longitudinally spaced apart circumferential grooves that separate the rod into a plurality of weight segments. The circumferential grooves facilitate separation of one or more of the weight segments from the rod. For example, a known grain rod comprises a plurality of separable weight segments each having a weight of about 10 grains. Thus, if it is desired to reduce the weight of the grain rod by 10 grains, then one of the segments is removed by cutting the grain rod at the circumferential groove between the first weight segment and the second weight segment at one end of the rod. However, it would be desirable to facilitate finer tuning or adjustment of the total weight and balance of the arrow without significantly increasing the number of circumferential grooves on the grain rod.
The invention provides a means for more quickly and easily attaching an arrowhead to an arrow shaft. The invention also facilitates better symmetry (e.g, concentricity and parallelism) of the arrowhead with the arrow shaft, thereby providing improved flight characteristics and accuracy. The invention also facilitates easy interchangeability of parts, whereby an arrowhead can be used with any of a variety of different arrow shafts having different diameters, or one type of arrowhead may be removed from an arrow shaft and replaced with another type of arrowhead.
In accordance with certain aspects of the invention, an improved grain rod for adjusting the total weight and balance of an arrow is provided. The improved grain rod facilitates finer adjustment of the weight and balance of an arrow without significantly increasing the complexity of the grain rod.
In accordance with one aspect of the invention, there is provided an arrow having a hollow arrow shaft, an arrowhead having a tip portion and a cylindrical shank portion, and a bushing having a cylindrical section and a tapered section. The cylindrical section of the bushing is received in an end of the hollow arrow shaft and secured to the hollow arrow shaft with an adhesive, and the tapered section has a bore in which the shank portion of the arrowhead is received. The shank portion of the arrowhead is secured within the bore with an adhesive.
In accordance with another aspect of the invention there is provided an arrow which includes a hollow arrow shaft having an inner diameter, an arrowhead having a tip portion and a cylindrical shank portion, and a bushing having a cylindrical section and a tapered section. A bore extends through the cylindrical section of the bushing. The bore has an inner diameter at the tapered section of the bushing that is matched to an outer diameter of the cylindrical shank portion of the arrowhead to accommodate receipt of the cylindrical shank portion of the arrowhead into the tapered section of the bushing. The cylindrical section of the bushing has an outer diameter matched to the inner diameter of the hollow arrow shaft to accommodate receipt of the cylindrical section of the bushing into an end of the arrow shaft. The cylindrical shank portion of the arrowhead has smooth surfaces that engage smooth surfaces of the bore extending through the tapered section of the bushing, whereby the absence of threads and other irregularities on the engaging surfaces between the arrowhead and the bushing improve concentricity among the arrowhead, bushing and arrow shaft.
In accordance with another aspect of the invention, there is provided a device for adjusting the weight and balance of an arrow. The device includes a rod having a plurality of longitudinally spaced apart circumferential grooves that define separable weight segments between the circumferential grooves. The rod includes at least one weight segment having a weight that is substantially different from the weight of another weight segment.